Sinusoidal wavelength-scanning superluminescent diode interferometer for two-dimensional step-profile measurement

2002 ◽  
Author(s):  
Osami Sasaki ◽  
Yasuhisa Shimakura ◽  
Takamasa Suzuki
Keyword(s):  
Profile Measurement ◽  
Two Dimensional ◽  
Superluminescent Diode ◽  
Wavelength Scanning

Two-dimensional density profile measurement with a sheet thermal Li beam on CPD

2007 ◽  
Vol 363-365 ◽  
pp. 1429-1435 ◽  
Author(s):  
H. Zushi ◽  
T. Morisaki ◽  
Y. Inada ◽  
J. Bouchard ◽  
K. Nakashima ◽  
...  
Keyword(s):  
Density Profile ◽  
Profile Measurement ◽  
Two Dimensional

scholarly journals An evaluation of ultrasonic arrays for the static and dynamic measurement of wheel–rail contact pressure and area

2020 ◽  
Vol 234 (10) ◽  
pp. 1580-1593
Author(s):  
Henry Brunskill ◽  
Andy Hunter ◽  
Lu Zhou ◽  
Rob Dwyer Joyce ◽  
Roger Lewis
Keyword(s):  
Contact Pressure ◽  
Ultrasonic Transducer ◽  
Dynamic Contact ◽  
Pressure Profile ◽  
Calibration Procedure ◽  
Railway Vehicle ◽  
Profile Measurement ◽  
Two Dimensional ◽  
Cross Sectional ◽  
Contact Conditions

The interfacial contact conditions between a railway vehicle wheel and the rail are paramount to the lifespan, safety and smooth operation of any rail network. The wheel–rail interface contact pressure and area conditions have been estimated, calculated and simulated by industry and academia for many years, but a method of accurately measuring dynamic contact conditions has yet to be realised. Methods using pressure-sensitive films and controlled air flow have been employed, but both are limited. Ultrasonic reflectometry is the term given to active ultrasonics in which an ultrasonic transducer is mounted on the outer surface of a component and a sound wave is generated. This ultrasonic wave packet propagates through the host medium and reflects off the contacting interface of interest. The reflected waveform is then detected and contact area and interfacial stiffness information can be extracted from the signal using the quasi-static spring model. Stiffness can be related to contact pressure by performing a simple calibration procedure. Previous contact pressure measurement work has relied on using a focusing transducer and a two-dimensional scanning arrangement which results in a high-resolution image of the wheel–rail contact, but is limited to static loading of a specimen cut from a wheel and rail. The work described in this paper has assessed the feasibility of measuring a dynamic wheel–rail contact patch using an array of 64 ultrasonic elements mounted in the rail. Each element is individually pulsed in sequence to build up a linear cross-sectional pressure profile measurement of the interface. These cross-sectional, line measurements are then processed and collated resulting in a two-dimensional contact pressure profile. Measurements have been taken at different speeds and loads.

Thin-film thickness profile measurement using wavelet transform in wavelength-scanning interferometry

2008 ◽  
Vol 46 (2) ◽  
pp. 179-184 ◽  
Author(s):  
Young-Min Hwang ◽  
Sung-Won Yoon ◽  
Jung-Hwan Kim ◽  
Souk Kim ◽  
Heui-Jae Pahk
Keyword(s):  
Thin Film ◽  
Wavelet Transform ◽  
Film Thickness ◽  
Profile Measurement ◽  
Thin Film Thickness ◽  
Thickness Profile ◽  
Wavelength Scanning

Square Layout Four-Point Method for Two-Dimensional Profile Measurement and Self-Calibration Method of Zero-Adjustment Error

2018 ◽  
Vol 12 (5) ◽  
pp. 707-713 ◽  
Author(s):  
Hiroki Shimizu ◽  
◽  
Ryousuke Yamashita ◽  
Takuya Hashiguchi ◽  
Tasuku Miyata ◽  
...  
Keyword(s):  
Calibration Method ◽  
Recurrence Equation ◽  
Profile Measurement ◽  
Two Dimensional ◽  
Measuring Point ◽  
Self Calibration ◽  
Displacement Sensors ◽  
Adjustment Error ◽  
Scan Line ◽  
Height Data

An on-machine measurement method, called the square-layout four-point (SLFP) method with angle compensation, for evaluating two-dimensional (2-D) profiles of flat machined surfaces is proposed. In this method, four displacement sensors are arranged in a square and mounted to the scanning table of a 2-D stage. For measuring the 2-D profile of a target plane, height data corresponding to all measuring points are acquired by means of the raster scanning motion. At the same time, pitching data of the first primary scan line and rolling data of the first subsidiary scan line are monitored by means of two auto-collimators to compensate for major profile errors that arise out of the posture error. Use of the SLFP method facilitates connection of the results of straightness-measurements results obtained for each scanning line by using two additional sensors and rolling data of the first subsidiary scan line. Specifically, the height of a measuring point is calculated by means of a recurrence equation using three predetermined height data for adjacent points in conjunction with data acquired by the four displacement sensors. Results of the numerical simulation performed in this study demonstrate higher efficiency of the SLFP method with angle compensation. During actual measurement, however, it is difficult to perfectly align inline the origin height of each displacement sensor. With regard to the SLFP method, zero-adjustment error is defined as the relative height of a sensor’s origin with respect to the plane comprising origins of the other three sensors. This error accumulates in proportion to number of times the recurrence equation is applied. Simulation results containing the zero-adjustment error demonstrate that accumulation of the said error results in unignorable distortion of measurement results. Therefore, a new self-calibration method for the zero-adjustment error has been proposed. During 2-D profile measurement, two different calculation paths – the raster scan path and orthogonal path – can be used to determine the height of a measurement point. Although heights determined through use of the two paths must ideally be equal, they are observed to be different because accumulated zero-adjustment errors for the two paths are different. In view of this result, the zero-adjustment error can be calculated backwards and calibrated. Validity of the calibration method has been confirmed via simulations and experiments.

TWO-DIMENSIONAL VELOCITY VECTOR PROFILE MEASUREMENT ON BUBBLY FLOW USING ULTRASONIC TECHNIQUE

2019 ◽  
Vol 2019.27 (0) ◽  
pp. 2257
Author(s):  
Wongsakorn Wongsaroj ◽  
Jevin Tanius Owen ◽  
Hideharu Takahashi ◽  
Natee Thong-un ◽  
Hiroshige Kikura
Keyword(s):  
Velocity Vector ◽  
Bubbly Flow ◽  
Profile Measurement ◽  
Ultrasonic Technique ◽  
Two Dimensional

Sinusoidal wavelength-scanning interferometer for profile measurement of metal surfaces

2012 ◽  
Author(s):  
Osami Sasaki ◽  
Takahiro Kurashige ◽  
Samuel Choi ◽  
Takamasa Suzuki
Keyword(s):  
Metal Surfaces ◽  
Profile Measurement ◽  
Wavelength Scanning ◽  
Scanning Interferometer
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